/**
 * 微信API工具类
 */
class WechatService {
  /**
   * 获取微信用户信息
   * @param {string} code 微信授权码
   * @returns {Promise<Object>} 微信用户信息
   */
  static async getUserInfo(code) {
    try {
      // 调用微信API获取用户信息
      // 实际项目中应该使用如下代码：
      /*
      const axios = require('axios');
      const appId = process.env.WECHAT_APPID;
      const secret = process.env.WECHAT_SECRET;
      
      // 获取访问令牌
      const tokenResponse = await axios.get(`https://api.weixin.qq.com/sns/oauth2/access_token?appid=${appId}&secret=${secret}&code=${code}&grant_type=authorization_code`);
      
      if (tokenResponse.data.errcode) {
        throw new Error(`获取微信访问令牌失败: ${tokenResponse.data.errmsg}`);
      }
      
      const { access_token, openid } = tokenResponse.data;
      
      // 获取用户信息
      const userInfoResponse = await axios.get(`https://api.weixin.qq.com/sns/userinfo?access_token=${access_token}&openid=${openid}&lang=zh_CN`);
      
      if (userInfoResponse.data.errcode) {
        throw new Error(`获取微信用户信息失败: ${userInfoResponse.data.errmsg}`);
      }
      
      return userInfoResponse.data;
      */
      
      // 模拟微信用户信息
      return {
        openid: `wx_${Math.random().toString(36).substring(2, 10)}`,
        nickname: `微信用户${Math.floor(Math.random() * 10000)}`,
        headimgurl: `https://via.placeholder.com/150?text=WX${Math.floor(Math.random() * 100)}`,
        sex: Math.floor(Math.random() * 2) + 1,
        language: 'zh_CN',
        city: '深圳',
        province: '广东',
        country: '中国',
        unionid: `wx_union_${Math.random().toString(36).substring(2, 10)}`
      };
    } catch (error) {
      console.error('获取微信用户信息失败:', error);
      throw new Error('获取微信用户信息失败');
    }
  }
  
  /**
   * 获取微信JS API配置
   * @param {string} url 当前页面URL
   * @returns {Promise<Object>} 微信JS API配置
   */
  static async getJsApiConfig(url) {
    try {
      // 实际项目中应该使用如下代码：
      /*
      const axios = require('axios');
      const crypto = require('crypto');
      
      // 获取访问令牌
      const appId = process.env.WECHAT_APPID;
      
      // 获取jsapi_ticket
      const ticketCache = await redis.get('wechat:jsapi_ticket');
      let ticket;
      
      if (ticketCache) {
        ticket = ticketCache;
      } else {
        // 获取访问令牌
        const tokenCache = await redis.get('wechat:access_token');
        let accessToken;
        
        if (tokenCache) {
          accessToken = tokenCache;
        } else {
          const tokenResponse = await axios.get(`https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${appId}&secret=${process.env.WECHAT_SECRET}`);
          accessToken = tokenResponse.data.access_token;
          await redis.set('wechat:access_token', accessToken, { EX: 7000 }); // 有效期稍小于2小时
        }
        
        // 获取jsapi_ticket
        const ticketResponse = await axios.get(`https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=${accessToken}&type=jsapi`);
        ticket = ticketResponse.data.ticket;
        await redis.set('wechat:jsapi_ticket', ticket, { EX: 7000 }); // 有效期稍小于2小时
      }
      
      // 生成签名
      const nonceStr = Math.random().toString(36).substring(2, 15);
      const timestamp = Math.floor(Date.now() / 1000);
      
      const string1 = `jsapi_ticket=${ticket}&noncestr=${nonceStr}&timestamp=${timestamp}&url=${url}`;
      const signature = crypto.createHash('sha1').update(string1).digest('hex');
      
      return {
        appId,
        nonceStr,
        timestamp,
        signature,
        url
      };
      */
      
      // 模拟微信JS API配置
      return {
        appId: 'wx123456789',
        timestamp: Math.floor(Date.now() / 1000),
        nonceStr: Math.random().toString(36).substring(2, 15),
        signature: Math.random().toString(36).substring(2, 15),
        url
      };
    } catch (error) {
      console.error('获取微信JS API配置失败:', error);
      throw new Error('获取微信JS API配置失败');
    }
  }
}

module.exports = WechatService;
